Answer: She started with $160.
It will take 6 weeks before she has less than half of what she originally invested.
Step-by-step explanation:
If her money is decreasing in value by 11% each week, it means that the rate at which it is decreasing is exponential.
We would apply the formula for exponential decay which is expressed as
A = P(1 - r)^t
Where
A represents the value of the investment after t weeks.
t represents the number of weeks.
P represents the initial value of the investment.
r represents rate of depreciation.
From the information given,
A = $142.40
r = 11% = 11/100 = 0.11
t = 1
Therefore
142.40 = P(1 - 0.11)^1
142.40 = P(0.89)
P = 142.4/0.89
P = 160
For her to have half of what she invested originally, then
80 = 160(0.89)^t
80/160 = (0.89)^t
0.5 = (0.89)^t
Taking log of both sides to base 10
Log 0.5 = log0.89^t = tlog0.89
- 0.3010 = - 0.051t
t = - 0.3010/- 0.051
t = 5.9
Approximately 6 weeks
Answer:
360 learners
Step-by-step explanation:
One way to solve these types of problems is that you could set up a proportion
learners/teachers = learners/teachers
Let x = no. of learners to enrol
30/1 = x/12
12(30) = x
x = 360 learners
Answer:
Number of cheaper dresses sold is 35
Number of expensive dresses sold is 15
Step-by-step explanation:
Given:
Cost of cheaper dresses = $90
Cost of expensive dresses = $140
Total cost of the dresses = $5250
To Find:
Number of cheaper dress = ?
Number of expensive dress = ?
Solution:
Let
The number of cheaper dresses be x
The number of expensive dresses be y
(Number of cheaper dresses X cost of cheap dress) + (Number of Expensive dresses X cost of expensive dress) = $5250
= $5250
It is given that the 20 more of the cheaper dresses than the expensive dresses is sold
So,
number of cheaper dress = 20 + number of expensive dress
x = 20 + y---------------------------------------(1)
y = 15
Substituting y in (1)
x = 20 +15
x= 35
Answer:
I don't think so.
Step-by-step explanation:
But what do I know? XD
